Method of extracting uranium, vanadium, and radium from ores and other material containing the same.



UNITED STATES PATENT OFFICE.

JOACHIM H. BURFEIND, OF NUCLA, COLORADb.

METHOD OF EXTRACTIING URANIUM, VANADIUM, AND RADIUM FROM 03153 A OTHER MATERIAL CONTAINING SAME.

No Drawing.

.7?) all whom it may 0012 earn:

Be it known that I, JonomarII. BUR- rnmn, a citizen of the United States, rcsiding at Nucla, in the county of Montroscand State of Colorado, have invented certain new and useful Improvements in Methods of 'Ilxtracting Uranium; Vanadium, and Radium from Ores and other Material Containing the Same; and 1 do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make use of the same.

My invention relates to the extraction of uranium, vanadium and radimn from ores and other materialcontaining uranium, vanadium and radium or either of them.

The process forming my invention is ap plicable to most ores in their natural state without a preliminary roasting or burning of the same although in other casesas, for

instance in ores carrying sulfids or much organic matter-a preliminary roasting or burning may be necessary.

Inasmuch as my invention has its chief field of usefulness in the extraction of uranium, vanadium and radium from ores requiring no preliminary roasting or burning the process will be described more particu larly in its application to ores of that charactor.

The object of the process, as usual in the art, is to finally obtain the uranium, vanadium and radium in a commercial form; but the main or principal features of the process which constitute my invention are, briefly, first the subjection of the'ores (either with or without previous roasting or burning' of the same, depending upon the character of the ore) to the action of sulfurous acid (as gas or in solution) to dissolve out the uranium and vanadium and to separate the radium bearing part from the worthless gangue. and, second, the separating of the solution conta ning the uranium and vanadium and the radium bearing part from the worthless gangue, and,third,the separating of the solution containing the uranium and vanadium from the undissolved part containing the radium values, and, fourth, the heating of the solution thus obtained to drive off the excess of sulfurous acid and form a precipitate containing uranium and vanadium, which may be subjected to any Specification of Letters Patent.

Application filed January 20, 1913. Serial No. 743,230.

Patented May' 5, 1914.

Sulfuric acid can seldom be bought in 10- calities where uranium and vanadium ores are found at less than three cents per pound, and in such localities frequently roast fumes can be had at a nominal cost, but Where there are no' roast fumesor gases and it is necessary to burn sulfur instead my method of treatment of ores or other material, above referred to, is still much cheaper. In places Where sulfuric acid costs three cents per pound sulfur will cost about thesame usually less, and a pound of sulfur inthe form of sulfurous acid will extract three times as much uranium and vanadium as sulfuric acid. It (sulfurous acid) being a much weaker acid than sulfuric acid, does not attack so vigorously the other metallic contents contained in the ores or material treated, thus not fouling the solution as much as when sulfuric acid is used. When using an excess of sulfurous acid it is not wasted but the excess used is recovered and used again for dissolving more uranium and vanadium from fresh charges as will be shown later on, while the excess used of sulfuric acid is not only wasted but consumes an extra amount of the precipitant (soda for instance) and also contaminates the product when lime is used as the precipitant. Neither does it (sulfurous acid) at- My method of treatment is carried out as follows: (A) Sulfurous acid is used in the form of gas. The ore or other material (crude, roasted or burned) is crushed to p tion 0 sufiicient water is added. The amount of water required will vary as the material under treatment varies and must be determined in each case; usually 1 part of water to 1 part of ore or material will answer. While this mixture is agitated sulfurous acid gas is conducted into the-mixture until the uranium and vanadium are dissolved and the part bearing the radium has separated from the gangue which latter is usually the case when the uranium and vanadium are in solution. The charge now consists of a solution containing the uranium and vanadium, an amorphous mud and the coarse gangue. By letting it settle a minute or longer, as may be required, the valueless heavy gangue settles to the bottom of the vessel, while the amorphous mud remains in suspension in the solution carrying the 'uranium and vanadium. Agitation is then stopped and the charging of sulfurous acid gas is discontinued. After permitting the mixture to settle for about one minute the solution carrying in suspension the radium bearin part is drawn off. A weak solusulfurous acid. is then run in and the mixture is again agitated either by sulfurous acid gas, air or mechanically for a few minutes, allowed to settle for about one minute and the wash water is drawn off. This washing is repeated until the gangue is practically free from uranium, vanadium and radium. The solution is run through filter press in which the amorphous mud bearing the radium is retained. The wash waters are also run through a filter press so as to free them from the radium contents. The solution is run into a precipitating vessel while the wash waters are used -for new charges instead of water used for the first charges. The solution is then heated until the excess of sulfurous acid gas has passed off. The sulfite salts of uranium and vanadium being insoluble in water are precipitated when the sulfurous acid which olds them in solution is driven off. But as during the operation some sulfates are formed which are soluble in water these will not be thus precipitated. 'At places where fuel is abundant and inexpensive the solution may be evaporated or the' usual precipitants may be used. If lime is used as the precipitant then sufiicient sulfurous acid should be left in the solution to retain excess usedin solution as lime acid sulfite. The precipitate after drying is ready for shipment. The radium bearing part is removed from the filter press and after drying is also ready for shipment. The gangue,

parts from the gangue.

unless it contains other valuable ingredients is discarded. I The excess of sulfurous acid, driven off by heating, is either allowed to be absorbed by water and then used to mix with fresh charges or it is directly charged into new charges with the other sulfurous acid gas. In either case it is reused for dissolving uranium and vanadium and for the separation of the radium hearing The wash waters containingsome sulfurous acid and uranium and vanadium are, as already mentioned, used for making the proper mixture of the ore for treatment so that nothing is wasted. (B) sulfurous acid is used in the form of solution. This mode of treatment is not recommended when the ore or material to be treated contains radium values, but may be used at places where roast fumes are abundant and can be had for the taking of them and the ores carry only uranium and vanadium or either of them. The solution of sulfurous acid is made in any way well known in the art. The ore or material to be treated crude, roasted or burnt is crushed to suitable size, placed ina yat, preferably with a filter bottom, such as are used in the old Plattner process or in cyaniding. The sulfurous acid solution is then permitted to percolate through the charge until a test shows that all the uranium and vanadium or either of them, as the case may be,

liable to be treated by my method is so small that 1t is out of the range of chemical analysis. In what form radium exists in the ores is as far as I know unknown. The fact that it is in a soluble form is easily demonstrated by disolving the ore in, say, hydrochloric acid; after washing the insolubles well they will be nonradio-active showing that the radium is in solution. All ores containing uranium and radium that I have met with, contain also barium in a soluble form. Sulfurous acid ('SO +XAq) dissolves this barium 'and forms barium sulfite (BaSO From results obtained I conclude that the SO +XAq also dissolves the radium present and that it is likewise soluble in the SO +XA q. Due to the presence of air durin the treatment of the ore by my method and possibly to secondary chemical reactions some'sulfates are formed and of course the most insoluble ones first which will soluble in sO -i-XAq. I

' phous mud alwaysformed when the ores in'question are treated with acids.

The treatment of the ore by my method is conducted in the cold with continuous agitation and gradual formation of su1-' fatesthe ideal conditions required to obtain the insoluble sulfates like barium sulfate in the amorphous condition and thus these amorphous sulfates enter the amor- The fact that in practice the radium and barium is not found in the valueless gangue verifies to a certain extent above theory for if'the ore was treated when hot with sulfuric acid the barium at least and most likely the'radium also would precipitate instantaneously and be mixed with the worthless gangue. However, it does ,not matter whether this theory is correct or not for in practice no radium is found in the gangue'the only part that is discarded when my method is used.. Thus when the uranium and vanadium bearing solution together with the radium bearing amorphous mudisv separated from the gangue as described all values in the ores are separated from the valueless gangue and after the amorphous mud is separated from the solution as described radium is separated from e uranium and vanadium.

Having described my invention, what I claim, and desire to secure by Letters Patent is-' v The process of extracting uranium, vanadium and radium Values from ores contain- "ing the same, which consists in the treating vof the ore with an aqueous solution of sulfur dioxid, whereby the uranlurn and va-- y signature in presence of. two 

